Sunday, February 16, 2014

When preparing and planning to install vCloud Director by VMware to provide a foundation of cloud services such as IaaS (Infrastructure as a Service), there are choices for which operating system can be used for some of the components.
Although there are choices, some are at no cost as they are freely distributable open source GNU licensed and others require a purchase to legally own and use the operating system for its intended use.

In the case of VMware vCloud Director installation and preparation, the choices for the operating system to use are all Linux based but can be Cent OS which is free and the other is Red Hat Enterprise Linux Server distribution which is not free - it is sold as a subscription. The lowest subscription is for two VMs and costs about the same as Windows Standard Edition server license. I do recall the time when it was free many years ago. The benefit is commercial support for the product. with Cent OS , your on your own except for tech forums.

Cent OS is freely downloadable and you may install it as many instances as needed both on physical systems and/or on virtual.

Failover then Failback of vCloud Director

For this VMware vCloud deployment, two Directors (vCD ) were installed. Two or more vCloud Directors can be load balanced by a typical http/https web load balancer. For this installation there were two but they were in a primary secondary configuration. The second director is a warm standby to the first. Failover was tested using two methods. One was to shut the vCloud Director VM off and the other was to just disconnect the virtual network interface card. The secondary vCloud Director started to take over fully at about 30 to 40 seconds in bot tests. No manual intervention was required. Failback of vCloud Director was not automatic. The secondary remained in charge and only when it was also turned off or the nic disabled was the a fallback.

As far as the installation of Cent OS for vCloud director, it had no real issues. The default install option of "Minimal" for Cent OS leaves too much networking and UI out to be a default for the VMware cloud solution. At a minimum, select Basic Server. Add desktops before by selecting Customize Now.

Issues or Problems using Cent OS for vCloud Director

The main and only issue encountered was the networking. One of the two system had an issue with routing. The vCloud Director installation requires two network interfaces for director. The ip addresses were assigned appropriately. Eth0 got one static ip address and the other network interface Eth1 was assigned another static ip address. They bot responded to pings however it was discovered that routing for these ping replies were coming from only one of the NICs . The other would see receive packets but never transmitted. One network interface card on the Cent OS was doing the transmitting for both nics.

This was fixed by modifying a configuration file related to routing at the Cent OS Linux level. This was not a VMware vCloud Director installation error.

Using Cent OS for VMware vCloud Director

I used Cent OS 6.4 x64 for a recent deployment of VMware vCloud Director. At the time of this writing Cent OS 6.5 was released, only a couple of months after the installation was completed. I recommend using Cent OS for vCloud Director. Neither server deployment has had any issues, not even a restart has been required since. The SSL certs also installed very easily with no issues, even swapping out the self signed certificate with a CA signed certificate presented no issue. You just nee to be able to work with a command line. It is proven to be fast enough to handle the role and on a tight budget, it is well worth it. Only minor issues were encountered that were easily solvable.